Calculating Contributing Area above sampling locations

I am trying to calculate the total area draining to a set of points (water quality sampling locations). I am not sure the best way to go about this.


At first I tried to treat them as pour points and try to delineate watersheds using the "Watershed" tool, but this did not work properly.

I am just trying to figure out a way to calculate the total area of contribution above a set of given points.


Any help would be greatly appreciated.


-Josh